Missing/Popping only at Idle

[BlackR33GTR]

Hey Guys,

I have a 95 R33 GT-R, pretty well stock with 96,000km.

it has

Apexi Super Suction intakes
Splitfire Coilpacks
New BCPR8ES gapped to .08mm
Megan Decat with stock exhaust.
Boost restrictor removed.

The car runs great, has great power but at idle it pops every second or so, but goes away after about 2000rpm.

Just wondering on your thoughts and where I should start as far as diagnosing

.

Thanks!
Alex Vandenberg

[RixR32]

Those plugs are too cold for a near stock setup. Id start there.
BCPR6EIX work well. Get the ones pre gapped at .8. NGK part # 5689 or something.
Don't get the -11

[BlackR33GTR]

Those plugs are too cold for a near stock setup. Id start there.
BCPR6EIX work well. Get the ones pre gapped at .8. NFL part # 5689 or something.
Don't get the -11

I had those plugs in the car when I first got the car and it did the same thing.

Sent from my SM-N900W8 using Tapatalk

[Skym]

Intake airleak after turbo's usually makes the engine miss at idle.

Or engine is running leaner than it should (lean missfire). Check fuel system, clean MAF's with CRC MAF cleaner or similar.

Sometimes it's a o2 sensor / ECU tune problem, especially if modified engine with breathing mods (common).

But it also could be a leaking coilpack which would explain the missing every 1 sec (firing order of engine).

[RATM]

My car's doing the same, been chasing this trouble for 1.5 years. Cold idle is perfect, slight pop when warm. I've posted a video just like you a year ago, same thing. Check your ECU, i have a Veilside ECU in mine. My guess it's maybe a bad tune for my car... But i'm having some normal reading on my wideband... I'm getting Ecutalk soon to help diagnotisc, i'm sick of these idle pop. I'll let you know if i find out something.

[Skym]

It's usually caused by the o2 sensor making ECU make engine go lean (lean missfire). If disable o2 sensor the engine stops missing at idle. ECU retune usually fixes the miss problem.

Also check the oil you are using, as sometimes it's too thick for the oil temps and timing via CAS (or faulty CAS) can be the other cause.

[caliber676]

I'd say from just hearing symptoms it's a vacuum leak. Usually the leak at idle will cause a/f ratio to change enough for a misfire, but above 2000rpm will not cause problems. Spray brake clean on all hoses, components that are under engine vacuum while the engine is running. A raise in rpm while spraying will locate your leak

[Skym]

Initially during warmup the o2 sensor is ignored by ECU, so that's why engine doesn't missfire and engine runs richer.

Also I agree with the sparkplugs, heatrange wise 6 is stock for RB25, RB26 (5 for RB20DET), 8's are too cold.

[Skym]

Initially during warmup the o2 sensor is ignored by ECU, so that's why engine doesn't missfire and engine runs richer.

Also I agree with the sparkplugs, heatrange wise 6 is stock for RB25, RB25 (5 for RB20DET), 8's are too cold.

Another is to check the mounting bracket for coilpack, type of coilpack (spring only or spring, piece on end of spring), as there are 2x different types of coilpacks and said to have different height / thickness mounting brackets on R32.